Chiral silicon Lewis acids having a pentacoordinate stereogenic silicon center: 29Si NMR studies and application to asymmetric Diels-Alder reactions.

The (29)Si NMR studies of chiral pentacoordinate silyl triflimides having a stereogenic center at silicon have revealed that a chiral silicon center is highly configurationally unstable. Such configurational instability has an enormously beneficial effect on the diastereo- and enantioselectivity of the catalytic asymmetric Diels-Alder reaction.